Ball point pen



Feb. 14, 1956 J. F. O'SULLIVAN 2,734,484

BALL POINT PEN Filed July 11. 1952 INKENTOR. JbMVA'OJUu/VAA/ BALL POINTPEN John F. OSullivan, Los Angeles, Calif., assiguor to FrawleyCorporation, Culver City, Calif., a corporation of CaliforniaApplication July 11, 1952, Serial No. 298,377

Claims. (Cl. 120-42.!)3)

My invention relates generally to writing instruments, and moreparticularly to a retractable type of ball point pen.

By reason of the ball nose assembly, and the character of the ink used,a ball pointed pen is not susceptible to leakage as is the conventionalfountain pen. Furthermore, only the very small outer surface of the ballis covered with wet ink, and may be easily protected by retractionwithin the pen barrel. For these reasons it is feasible to construct aball pointed pen with a slidable writing cartridge movable from anextended writing position to a retracted carrying position. This avoidsthe use of the inconvenient separate cap found on conventional pens,simplifying the construction, and providing a pen which is instantlyready for use.

This invention is concerned with a direct and positive acting operatingmechanism for moving the writing cartridge between carrying and writingpositions. In general, prior types of operating means have involvedcomplex mechanisms which are subject to frequent breakdowns, and havenumerous intricate parts which are expensive to manufacture anddiflicult to assemble. An embodiment of my invention has a minimumnumber of direct acting elements cooperating in such a manner that it isimpossible for the pen to jam or skip. The elements are economical tomanufacture, and so durable that the pen is substantially trouble-free.In addition, the complete mechanism is easily operated and quiteconvenient to use.

With the foregoing in mind, it is a major object of my invention toprovide an improved retractable ball point pen of simple and durableconstruction.

Another object of my invention is to provide an improved pen of theclass described having an operating mechanism which is convenientlyused, and not subject to accidental or unintentional movement.

It is also an object of my invention to provide an operating mechanismhaving a positive and direct acting operating plunger for urging awriting cartridge into an exposed writing position.

A further object of my invention is to provide simple and positivelocking means for holding the writing cartridge in extended position.

An additional object of my invention is to provide a side release buttonoperable to withdraw the writing cartridge, and so disposed that it doesnot interfere with the use of the instrument nor is it subject toaccidental release.

It is a still further object of my invention to provide an operatingmechanism having a minimum number of working parts, permitting an easyand rapid assembly.

These and other objects and advantages of my invention will becomeapparent from the following detailed description of a preferredembodiment thereof, and from an inspection of the accompanying drawings,in which:

Fig. 1 is a side elevation partially in section of a preferredembodiment of my invention;

Fig. 2 is an enlarged partial section of the upper opnited StatesPatent'O" Patented Feb. 14, 1956 crating mechanism showing the writingcartridge in withdrawn carrying position;

Fig. 3 is a view similar to Fig.2 showing the operating plungerdepressed;

Fig. 4 is an enlarged partial section of the operating mechanism showingthe writing cartridge in extended position;

Fig. 5 is a cross-section taken along the line 55 of Fig. 4;

Fig. 6 is an inverted perspective view of the locking sleeve; and

Fig. 7 is a cross-section taken along the line 7-7 of Fig. 1.

Referring now the drawings and particularly to Fig. 1 thereof, thenumeral 10 designates generally a pen housing or barrel formed as atapered cylindrical member of conventional configuration. In order topermit installation and replacement of an internal writing cartridge 11,barrel 10 is preferably formed of two-part construction comprising alower body 12 and an upper cap 13. Body 12 is provided with an enlargedaxial chamber 14 having upper threads 15 to take a threaded hub 16extended downwardly from cap 13. Extended through cap 13 is an axialchamber 18 of somewhat smaller diameter than chamber 14 and opening intothe upper end of the latter.

Writing cartridge 11 is formed as an elongated tubular shell whichextends through both chambers 14 and 18 and carries on'its lower end areduced stem 19 having a ball nose assembly 20 for engagement with thewriting paper. The front end of body 12 is open to slidably receive stem19 in a relatively loose fit, and is formed with an internal shoulder 21which abuts against the end of the tubular shell of cartridge 11 andlimits its outward extension. In this position, stem 19 is projectedoutwardly from body 12 to expose nose assembly 20 for writing, as shownin phantom outline. The lower intermediate section of cartridge 11 formsan ink reservoir which is in communication with nose assembly 20 throughstem 19. As the ball of the nose assembly rotates, it picks up a thinfilm of ink from the interior of stem 19 and moves it outwardly fortransfer to the surface of the writing paper.

Surrounding the lower portion of cartridge 11 is a spring means in theform of a coil spring 24 which is limited in downward movement byengagement at its lower end with the wall of chamber 14. The upper endof spring 24 engages a crimped projection 25 formed on cartridge 11 insuch a position as to cause the spring to be compressed when thecartridge has moved downwardly to the writing position. Thus, spring 24continuously urges cartridge 11 to retract upwardly to a carryingposition in which nose assembly 20 is confined within body 12.

In order to move cartridge 11 downwardly to the writing position, Iprovide an upper operating mechanism which includes an operating plunger26 having a head 27 which projects outwardly from the top of cap 13 formanual actuation. For ease of assembly I prefer to form cap 13 ofbuilt-up construction with a solid plastic core or insert member 28press-fitted Within an outer metal cover 29. Insert 28 is terminatedshort of the top of cover 29, and defines an enlarged open space 30which lies above the upper end of chamber 18. At one side of cover 29 isa spring pocket clip 31 which is secured firmly at its upper end to thewall of the cover, and has a downwardly projecting arm formed with thecon ventional balled tip for attaching the pen to the fabric of apocket, or the like.

Plunger head 27 is slidably fitted within a suitable opening formed inthe top of cover 29, and upward movement of the plunger is limited by astop collar 34 which lies within space 30 and is adapted to abut againstthe inner wall of the cover when the actuating head is in a raisedposition. The lower end portion of plunger 26 is slidably fitted withina locking sleeve 35 secured within the top of insert 28 so that theplunger is constrained for sliding movement along the longitudinal axisof the pen. A coil spring 36 surrounds plunger 26 and is seated betweenthe upper end of sleeve 35 and stop collar 34 to urge the plungerupwardly with head 27 in an exposed position.

Extending the entire length of chamber 18 along one side thereof is anoffset portion 37, as can best be seen in Figs. 4 and 5. The upper orrear end of offset por* tion 37 is terminated by the end wall of sleeve35 which forms in effect an internally overhanging locking shoulder orprojection 38. Offset portion 37 is smoothly joined to chamber 18 and isof such a cross-sectional size that cartridge 11 may shift laterallyaway from the axis of chamber 14 into a position beneath shoulder 38.The offset portion 37 may be said to impart an elliptical cross sectionto the chamber or cause the chamber and its offset portion 37 to beeccentric with respect to the axis of chamber 14 and the axis of theplunger 26. As was previously mentioned, cartridge stem 19 has arelatively loose fit within the lower end of body 12, permitting the topof cartridge 11 to rock freely toward or away from the axis of chamber18. The external diameter of cartridge 11 is such that it will slideupwardly within sleeve 35 when aligned with the axis of chamber 18.However, when cartridge 11 is offset into portion 37, the top rim of thecartridge bears against shoulder 38 and limits upward movement thereof.When cartridge 11 is positioned beneath shoulder 38, the lower noseassembly 20 is extended outwardly through the bottom of body 12 inwriting position.

For the purpose of moving cartridge 11 downwardly into the writingposition and shifting it laterally beneath shoulder 38, the lower end orfoot of plunger 26 is provided with a pair of laterally spaced teeth 40and 41 having bottom surfaces inclined upwardly and outwardly in thedirection of shoulder 38. The surface of tooth 40 adjacent shoulder 38bears upon the corresponding rim portion of the tubular shell ofcartridge 11, while the surface of tooth 41 bears upon the opposite rimportion of the cartridge.

With cartridge 11 retracted upwardly into the carrying position as shownin Figs. 1 and 2, thumb pressure upon plunger head 27 moves plunger 26downwardly, driving the cartridge with it by reason of the engagement ofteeth 40 and 41. During this portion of the movement, teeth 40 and 41are both engaged with the rim of cartridge 11, but tooth 40 has contactwith the inner edge of the rim wall, and exerts a greater lateral forceupon the cartridge than does tooth 41 should there be any slightmisalignment or wear of the working surfaces.

After the top of cartridge 11 has passed below shoulder 38, the lateralcamming action of tooth 40 forces the cartridge to shift laterally awayfrom the axis of chamber 18 and into offset portion 37. However, themaximum lateral throw which can be exerted by tooth 40 is limited by thethickness of the wall of cartridge 11. After tooth 40 has slipped withincartridge 11, as shown in Fig. 3, tooth 41 continues the camming actionand moves the cartridge outwardly further into offset portion 37. Thusthe cartridge 11 is shifted laterally a sufficient distance to hookfirmly beneath shoulder 38, and nose assembly 29 is locked outwardlyinto the writing position.

To prevent any accidental dislodgement of cartridge it from beneathshoulder 38 due to the pressure exerted on nose assembly 20 in writing,sleeve 34 is formed with a downwardly projecting lip 43 at the inneredge of shoulder 38. As is best seen in Fig. 6, lip 43 is formed with astraight inner edge and an upwardly tapered outer surface. This taperedouter surface of lip 43 permits the cartridge 11 to be dislodged frombeneath shoulder 38 by a straight side thrust, but at the same timeprevents accidental sliding movement. In order to hold plunger 26against rotation within sleeve 34 and maintain teeth 40 and 41 in theproper position relative to shoulder 38, I provide a small pin or key 44projected inwardly from the inner surface of the sleeve. Key 44 slidesin a keyway 45 extended longitudinally along plunger 26, as is best seenin Fig. 7.

I have thus far described the components of the operating mechanism bywhich the cartridge 11 is moved downwardly from the carrying position tothe writing position. It can also be understood that releasing meansmust be provided for dislodging cartridge 11 from beneath shoulder 38 sothat it can again be moved upwardly to the carrying position under theurging of spring 24. To this end I provide a releasing button 46extended radially through the side wall of cap 13 into offset portion 37and spaced downwardly below shoulder 38. Preferably, button 46 is spacedperipherally from pocket clip 31 so that the releasing action isentirely independent of the action of the clip.

Button 46 has a head 47 projecting outwardly through cap cover 29, andis slidably mounted for limited movement in the wall of insert 28 withthe inner end being adapted to bear against the side of cartridge 11. Tolimit the movement of button 46, an enlarged collar 48 is constrainedfor movement between a reduced journal bushing 49 formed at the inneredge of insert 28, and a reduced opening 50 formed in cover 29. For easeof assembly, button 46 is of such length that it may be moved intoinsert 28 while cover 29 is pressed on, and is thereafter locked inplace by the cover. When cartridge 11 is locked downwardly in thewriting position as shown in Fig. 4, button 46 is pushed outwardly sothat head 47 is raised from the surface of cover 30. By pressinginwardly on head 47, cartridge 11 is pushed laterally out of offsetportion 37 and into alignment with the axis of chamber 18. This, ofcourse, releases cartridge 11 from beneath shoulder 38 and lip 43 sothat it is free to slide upwardly within sleeve 35 and into theretracted carrying position.

While I have thus shown and described a preferred embodiment of myinvention in detail, variations of design and construction will beapparent to those skilled in the art. Therefore, I do not wish to belimited to the preferred embodiment, except as defined in the appendedclaims.

I claim:

1. A ball point writing instrument comprising: a barrel having an openfront end and an inner axially extending chamber formed with an internalside projection at the rear end thereof; a tubular writing cartridgehaving an ink reservoir and a ball point assembly, said cartridge beingloosely mounted in said barrel for sliding movement from an enclosedcarrying position to an exposed writing position extended through saidopen end, the rear end of said cartridge being rockable away from theaxis of said barrel; spring means urging said cartridge toward saidcarrying position; operating means including an op crating plungermounted at the rear end of said barrel and constrained for axialslidingmovement, said plunger having a foot formed with laterally spacedinclined teeth, one of said teeth engaging the rim of said cartridgeadjacent said projection to shift said cartridge away from the axis ofsaid barrel and beneath said projection, and the other of said teeththereafter engaging the opposite side of the rim of said cartridge forcontinuing the lateral shifting movement to securely position saidcartridge under said projection whereby upon the rearward retraction ofsaid plunger said cartridge is held in writing position; and means forreleasing said cartridge from beneath said shoulder for retraction tosaid carrying position.

2. A ball point writing instrument comprising: a barrel having an openfront end and an inner axially extending chamber formed with an offsetportion at one side thereof terminated rearwardly by an overhangingshoulder; a tubular writing cartridge having an ink reservoir and a ballpoint assembly, said cartridge being loosely mounted in said barrel forsliding movement from an enclosed carrying position to an exposedwriting position extended through said open end, the rear end of saidcartridge being movable laterally from the axis of said barrel to aposition within said offset portion; spring means urging said cartridgetoward said carrying position; operating means including an operatingplunger mounted at the rear end of said barrel and constrained for axialsliding movement alongside said shoulder, said plunger having a footformed with laterally spaced inclinedteeth, one of said teeth engagingthe rim of said cartridge adjacent said shoulder to shift said cartridgeaway from the axis of said barrel and beneath said shoulder upon forwardmovement of said plunger, and the other of said teeth thereafterengaging the opposite side of the rim of said cartridge for continuingthe lateral shifting movement to securely position said cartridge undersaid shoulder whereby upon the rearward retraction of said plunger saidcartridge is held in Writing position; and a releasing button mountedfor lateral sliding movement in said barrel, said button having a headprojecting outwardly from the side of said barrel and an inner end forengagement with the side of said cartridge to release said cartridgefrom beneath said shoulder for retraction to said carrying position.

3. A ball point writing instrument comprising: a barrel having an openfront end and an inner axially extending chamber formed with an offsetportion at one side thereof terminated rearwardly by an overhangingshoulder, said shoulder having a downwardly projecting inner lip; atubular writing cartridge having an ink reservoir and a ball pointassembly, said cartridge being loosely mounted in said barrel forsliding movement from an enclosed carrying position to an exposedwriting position extended through said open end, the rear end of saidcartridge being movable laterally from the axis of said barrel to aposition within said offset portion; spring means urging said cartridgetoward said carrying position; operating means including an operatingplunger mounted at the rear end of said barrel and constrained for axialsliding movement alongside said shoulder, said plunger having a footformed with laterally spaced inclined teeth, one of said teeth engagingthe rim of said cartridge adjacent said shoulder to shift said cartridgeaway from the axis of said barrel and beneath said shoulder upon forwardmovement of said plunger, and the other of said teeth thereafterengaging the opposite side of the rim of said cartridge for continuingthe lateral shifting movement to securely position said cartridge rimoutside of said shoulder lip whereby upon the rearward retraction ofsaid plunger said cartridge is held in writing position; spring meansurging said plunger toward said rearward retracted position; and areleasing button mounted for lateral sliding movement in said barrel,said button having a head projecting outwardly from the side of saidbarrel and an inner end for engagement with the side of said cartridgeto release said cartridge from beneath said shoulder for retraction tosaid carrying position.

4. A ball point writing instrument comprising: a barrel having an openfront end and an inner axially extending chamber formed with an offsetportion at one side thereof; a sleeve fitted within the rear end of saidbarrel and'having an end providing a shoulder overhanging said offsetportion, said end having a downwardly projecting lip at the inner edgethereof'formed with a rearwardly inclined outer surface; a tubularwriting cartridge having an ink reservoir and a ball point assembly,said cartridge being loosely mounted in said barrel for sliding movementfrom an enclosed carrying position to an exposed writing positionextended through said open end, the rear end of said cartridge beingmoveable laterally from the axis of said barrel to a position withinsaid offset portion; spring means urging said cartridge toward saidcarrying position; operating means including an operating plungermounted for sliding movement within said sleeve, said plunger having afoot formed with laterally spaced inclined teeth, one of said teethengaging the rim of said cartridge adjacent said shoulder to shift saidcartridge away from the axis of said barrel and beneath said shoulderupon forward movement of said plunger, and the other of said teeththereafter engaging the opposite side of the rim of said cartridge forcontinuing the lateral shifting movement to securely position saidcartridge rim outside of said sleeve lip whereby upon the rearwardretraction of said plunger said cartridge is held in writing position;spring means urging said plunger toward said rearward retractedposition; and a releasing button mounted for lateral sliding movement insaid barrel, said button having a head projecting outwardly from theside of said barrel and an inner end for engagement with the side ofsaid cartridge to release said cartridge from beneath said shoulder forretraction to said carrying position.

5. A ball point writing instrument comprising: a barrel having an openfront end and an inner axially extending chamber formed with an offsetportion at one side thereof; a sleeve fitted within the rear end of saidbarrel and having an end providing a shoulder overhanging said offsetportion, said end having a downwardly projecting lip at the inner edgethereof formed with a rearwardly inclined outer surface; a tubularWriting cartridge having an ink reservoir and a ball point assembly,said cartridge being loosely mounted in said barrel for sliding movementfrom an enclosed carrying position to an exposed writing positionextended through said open end, the rear end of said cartridge beingmovable laterally from the axis of said barrel to a position within saidoffset portion; a coil spring positioned Within the front end of saidchamber and engaging said cartridge to urge said cartridge toward saidcarrying position; operating means including an operating plungermounted for sliding movement within said sleeve, said plunger having afoot formed with laterally spaced inclined teeth, one of said teethengaging the rim of said cartridge adjacent said shoulder to shift saidcartridge away from the axis of said barrel and beneath said shoulderupon forward movement of said plunger, and the other of said teeththereafter engaging the opposite side of the rim of said cartridgeforcontinuing the lateral shifting movement to securely position saidcartridge rim outside of said sleeve lip whereby upon the rearwardretraction of said plunger said cartridge is held in writing position;key means mounted on said sleeve and said plunger for holding saidplunger against rotation therein; a coil spring mounted rearwardly ofsaid sleeve and surrounding said plunger for urging said plunger towardsaid rearward retracted position; and a releasing button mounted forlateral sliding movement in said barrel, said button having a headprojecting outwardly from the side of said barrel and an inner end forengagement with the side of said cartridge to release said cartridgefrom beneath said shoulder for retraction to said carrying position.

References Cited in the file of this patent UNITED STATES PATENTS2,584,569 Frentzel Feb. 5, 1952 2,587,935 Wall-ace Mar. 4, 19522,693,170 Sears Nov. 2, 1954 FOREIGN PATENTS 273,976 Switzerland June 1,1951

